Fade in custom made beaver themer header

Beaver Themer
1

Hey folks, is there an easy way to display / fade in a custom created beaver themer header after scrolling the page for 300px? I could not use the beaver builder menu in the customizer so i had to use custom beaver themer menu.

Big header
Sticky small header

I’d like the “small header” to fade in on the home page after scrolling for about 300px.

2

Hey tribe, i found a piece of javascript and used it along with a beaver themer part.
It works only on scroll up on the home page.
CodePen JS
This solution works for me, althought i have only tested it in Firefox so far.
The problem i see - now i have two identical navigation bars - is this a problem for seo?